What is it that makes Nascar cars so safe during crashes? I’ve seen cars wreck out at nearly 200mph and it looks like a bumper car crash.

Question

I’ve seen Nascar crashes where a car going 180 goes sideways into a wall, and then gets t-boned by other cars that were also going 180 mph and yet no rollover and the cars barely look damaged and everyone walks away unscathed. Meanwhile normal passenger cars go sideways doing 50mph and they roll over 6 times, gets demolished, and kills the driver. What is it about Nascar cars that make them so crash resistant/resilient?

In: Engineering

Answer 1

Great answers here but I think there is something missing…that gets to the heart of what you are asking OP.

Race car safety is a different game than street car safety.

Street car safety strategy: provide the greatest chance of survival and minimum level of injuries for the minimally restrained occupants of the car in a crash that likely involves a single major impact. Do this by sacrificing part the structure of the car to slow down the energy transfer (the crumple zone). Minimizing injuries by from initial impact is more important than preserving the structure for subsequent impacts.

Race car safety: provide the greatest chance of survival for a maximally restrained occupant, in a crash that involves likely multiple major impacts. The safety structure must maintain integrity after initial impact. surviving subsequent impacts is more important than slowing down energy transfer to the occupant.

Yes it’s a gross generalization, a modern street car does have a safety cage, and a modern race car safety cage does absorb some impact energy. Nothing is black and white. But the concepts of safety are fundamentally different between the two.

A roll cage is designed to keep its shape, and to keep the occupant contained within it. Race cars don’t have crumple zones like a street car. The impacts of a crash are harsher on the human body than a crash in a street car. That’s why the driver is harnessed, with a helmet, restricted head movement, HANS device etc. it’s not just about the speed. It’s needed to keep the driver alive given the car structure cannot simply sacrifice itself to “cushion” an impact because it it is expected to potentially withstand the next impact, and the next impact, and the next…